Let C(x)=2x+ 550 and R(x) = 28x. (a) Write the profit function P(x). P(x) = I (b) What is the slope m of the profit function? m = (c) What is the marginal profit MP? MP = (d) Interpret the marginal profit. Each additional unit sold increases the profit by this much. This is the smallest number of units that can be sold in order to make a profit. The profit is maximized when this many units are sold. Each additional unit sold decreases the profit by this much.